1. Field of the Invention
The present invention relates to a dispenser of paste material, such as toothpaste, that has an outer housing with an open upper side and a dome at the lower side. The roof of the dome bears a closing body of an air entry valve. The closing body is pushed into an open position in the presence of a negative pressure in the outer housing. The dispenser also has an inner housing that projects upwardly from the outer housing. The inner housing, on its headpiece, has an application surface and a nozzle opening. Via the application surface, the inner housing can be pushed in opposition to the spring force provided by a bellows in the outer housing, the outer housing itself being sealed off from the inner housing, with the result that, when this application of force takes place, a transport slug, which travels within the inner housing in the direction of the nozzle opening, pushes material ahead of itself in response to air pressure that has accumulated behind it.
2. Description of the Related Art
A dispenser of the type described above is known from EP 0 648 180 B1. The air entry valve disclosed therein is comprised of a strip, made from rubber or synthetic material, that is fastened at the edges at both ends. The strip extends over a centrally disposed airflow opening in the roof of the dome. The strip, at its periphery, extends in the dispensing direction by way of a collar. For securing purposes, a valve chamber, formed as a pot, is closed by way of a cap that can be snapped in place. The valve chamber is perforated. The cap covers the valve body and limits its curvature.
Beyond this, the prior art also presents peripherally hinged valve shutters as well as ball valves. The former concept presupposes a high level of precision in assembly, while ball valves have the disadvantages associated with inlet components that experience excessive force.
An object of the present invention is to simplify a conventional dispenser in terms of the manner in which its the air entry valve is constructed, as well as to increase the dispenser's functional reliability.